In an LTE (Long Term Evolution, long term evolution) system, a UE (User Equipment, user equipment) obtains uplink synchronization and uplink resources through a random access procedure (Random Access Procedure). In a contention-based random access procedure, the UE randomly selects a RAP from a group of RAPs (Random Access Preambles, random access preambles) and initiates random access. After receiving a RAR (Random Access Response, random access response), the UE sends an Msg3 (the third message of the random access), and carries in the Msg3 a CCCH SDU (Common Control Channel Serving Data Unit, common control channel serving data unit) or a C-RNTI (Cell Radio Network Temporary Identifier, cell radio network temporary identifier) of the UE according to the purpose of initiating the random access. After sending the Msg3, the UE starts a CRT (Contention Resolution Timer, contention resolution timer). The UE considers that the contention is successful if receiving a contention resolution message before the CRT expires. The UE performs backoff for a period of time and reinitiates random access if the contention resolution fails after the CRT expires.
In the prior art, if it is a MAC (Media Access Control, media access control) of the UE that initiates the random access procedure, and the Msg3 transmits the C-RNTI, which is used as a control unit of the MAC, the UE considers that the contention resolution is successful after receiving UL Grant (uplink grant) that is sent by an eNB (Evolved NodeB, Evolved NodeB), masked with the C-RNTI and transmitted over new data; the UE considers that the contention resolution fails, performs backoff for a period of time, and reinitiates random access if receiving no UL Grant transmitted over the new data after the CRT expires.
However, in the prior art, during wait time after the UE sends the Msg3, if receiving DL Assignment or UL Grant, where the DL Assignment (downlink assignment) or UL Grant is masked with a T C-RNTI (Temporary C-RNTI) that is allocated by the eNB to the UE, the UE does not process the information, which may cause that the UE cannot timely judge whether the contention resolution is complete, and therefore, may cause that time for reinitiating random access is delayed.